Electric cable terminal



Jan. 8, 1935. F. c. MEYER ET AL ,9

ELECTRIC CABLE TERMINAL Filed Dec. 21, 1932 I ll II 6 INVENTORtS. 7 By @7705 Z ATTORNEYS.

Patented Jan. 8, 1935 UNITED STATES PATENT OFFICE ELECTRIC CABLE TERLHNAL Application December 21, 1932, Serial No. 648,170

SC'la-ims.

This invention is directed to a pothead or ter-' the insulated conductor or conductors of the cable being submerged in oil or other insulating fluid under high pressure with which the pipe is filled.

In the accompanying drawing:

The flgure is a sectional elevation of one embodiment of the invention.

Referring to the drawing in detail, 1 designates the conductor of the cable and 2 the pipe in which the cable is drawn and which is kept filled with oil or other insulating fluid designated 3 maintained under high pressure. About the paper insulation of the conductor 1 is a shielding metal tape or braid 4 terminating at 5.

The end of the pipe 2 is threaded externally for the reception of a gland 6 which is screwed thereon. Bolted to this gland is a flange 7 screwed upon the lower end of a sleeve or bushing 8 which is in line with the pipe or conduit 2 and surrounds the insulated conductor 1. The lower part of this bushing or sleeve 8 is tapered to facilitate entry of the insulated conductor thereinto and contacts with the metal tape or braid 4 adjacent the termination thereof.

The bushing or sleeve 8 is threaded intermediate its ends as shown at '9 to receive the metal flange or ring 10 to which is bolted a metal cone 11, bronze for example, constituting the lower part of the pothead proper. This cone 11 is provided at 12 with a filler opening for fllling the interior of the pothead with oil or other suitable insulating fluid 13 which is under gravity pressure as distinguished from the high pressure under which the insulating fluid 3 in the pipe 2 is maintained.

The upper end of the sleeve or bushing 8 is threaded internally for receiving the lower end of a pressure tube 15 of insulating material which extends upwardly toward the top of the pothead construction and which as will be seen from the drawing receives the insulated conductor of the cable. The internal diameter of the pressure tube 15 is a trifle larger than the external diameter of the insulating paper 16 of the conductor to permit of maintaining the insulated conductor immersed in the insulating fluid with which the pressure tube 15 is fllled and which insulating fluid is at all times incommunication with the insulating fluid 3 in the pipe 2 and hence under high pressure.

The upper end 17 of the conductor of the cable is provided with a fitting 18 soldered, welded or otherwise suitably attached in permanent fashion to the conductor, the upper end or stem of this fltting being threaded externally as shown at 19. Screwed onthe upper end of the pressure tube 15 is a metal fitting 20 provided with a central bore which is larger than the stem of the fitting l8. Bolted to this metal fitting or ring 20 is a plate 22, the stem of the fitting 18 being provided with a nut 23 for pulling the connector or fltting 18 up against the plate 22.

The plate 22 receives a tube 24 extending upwardly to the exterior of the terminal for venting purposes.

Surrounding the pressure tube 15 adjacent the lower end thereof is a metal cone 25, the lower end of this cone abutting the upper end of the sleeve or bushing 8. This cone and the sleeve or bushing 8 are united by a wipe joint 26.

The upper end of the cone 11 above referred to is flared outwardly to provide a support for the porcelain sleeve 2'7 of the terminal, the lower end of this sleeve being cemented to a ring 28 which is bolted to the base of the cone 11, a washer 29 being interposed between the base of sleeve 27 and ring 28 and the cone 11 to provide a fluid-tight joint.

The upper end of the insulatingsleeve 27 is cemented to a ring 30 and to this is bolted a cap plate 31.

The threaded stem of the connector 18 extends upwardly through the cap plate 31, the stem being equipped with 'a nut 32.

It will be understood that this stem is sweated to the plate 31 or packed so as to provide a liquidtight construction.

The plate 31 is equipped with a vent 33 for the escape of air when the terminal is originally fllled with oil, this vent eventually of course being plugged.

Within the pothead and resting upon the cone 25 are barrier tubes 34 which may be of paper or other suitable material.

What we claim is:

1. A terminal for electric cables of the pressure type comprising in combination a sleeve bolted to the end of the oil'filled cable pipe and providing a continuation thereof, the bore of said sleeve being tapered to facilitate drawing of the insulated cable conductor therethrough, a pressure tube screwed into the upper end of said sleeve, and receiving the cable conductor, the upper end of said tube being sealed, a cone mounted on the upper end of said sleeve and wiped thereto, barrier tubes supported by said cone, a ring threaded on the outside of said sleeve intermediate its ends,

a cone supported thereby and bolted thereto, an insulator surrounding said barrier tubes and pressure tube supported by said last mentioned cone,

said insulator being sealed top and bottom, the said pressure tube being in communication with the pipe'of the cable at all times, and oil under gravity pressure filling the space within the terminal exteriorly of the pressure tube.

- 2. A terminal for electric cables of the pressure type comprising in combination a sleeve secured to the end of the oil filled cable pipeand providing a continuation thereof, a pressure tube screwed into the upper end of said sleeve and receiving the insulated cable conductor, the upper end of said tube being sealed, a cone mounted on the upper end of said sleeve and secured thereto, barrier tubes supported by said cone, a cone below the first mentioned cone and supported by said sleeve, an insulator surrounding said barrier tubes and pressure tube and supported by said last mentioned cone, said insulator being sealed top and bottom, said first mentioned cone flaring to its maximum diameter within said insulator, said pressure tube communicating with the cable pipe at all times, and oil under-gravity pressure filling the space within the terminal exteriorly of the pressure tube. I

3. A terminal for electric cables of the pressure type comprising in combination a sleeve bolted to the end of the oil filled cable pipe and providing a continuation thereof, a pressure tube screwed into the upper end of said sleeve, and receiving the cable conductor, the upper end of said tube being sealed, a cone mounted on the upper end of said sleeve and wiped thereto, barrier tubes supported by said cone, a ring threaded on the outside of said sleeve intermediate its ends, a cone supported thereby and bolted thereto, an insulator surrounding said barrier tubes and pressure tube supported by said last mentioned cone,'said insulator being sealed top and bottom, the said pressure tube being in communication with the pipe of the cable at all times, and oil under gravity pressure filling the space within the terminal exteriorly of the pressure tube.

4. A terminal for electric cables of the pressure type comprising in combination asleeve secured to the end of the oil filled cable pipe and providing a continuation thereof, a pressure tube screwed into the upper end of said sleeve, and receiving the insulated cable conductor, means for sealing the upper end of said tube, a cone about the lower part of said pressure tube and mounted on the upper end of said sleeve and wiped thereto, barrier tubes surrounding said pressure tube and supported by said cone, said barrier tubes being spaced from each other and gradually decreasing in length at their upper ends outwardly from said pressure tube, a conical member below the first mentioned cone secured to said sleeve, an insulator supported by said conical member, said insulator surrounding said pressure tube, barrier tubes and the first mentioned cone, the first mentioned cone flaring to its maximum diameter within said insulator, means for sealing said insulator top and bottom, said pressure tube communicating with the pipe of the cable at all times, and oil under gravity pressure filling the space within the terminal exteriorly of the pressure tube.

5. A terminal for the end of a high pressure oil filled conduit containing an insulated cable comprising in combination a sleeve sealed to the end of the conduit and providing a continuation thereof, an insulating high pressure tube sealed to and extending beyond the sleeve and spacially surrounding the end of the insulated cable, a conductor terminal sealed to the upper end of the insulating high pressure tube and connected to the conductor of the cable, a static stress distributor surrounding the lower end of the insulating high pressure tube and having electrical connection with the sleeve, 9. second insulator tube spacially surrounding the high pressure tube and the distributor and sealed to the terminal, means extending from the sleeve supporting the second insulator tube and in sealed relation therewith and oil under low pressure filling the inclosure between the two tubes.

FRED C. MEYER.

GEORGE E. MOFFITT. 

